(1) Field of the Invention
The present invention relates to a detectable heavy duty needle cannula for use in hypodermic syringes and the like. The needle cannula comprises a magnetized stainless steel alloy, which enables the needle cannula to be detectable in metal detectors that are commonly used in the meat processing industry to detect broken needle cannulas in the flesh of slaughtered animals. The needle cannula further comprises a sidewall that is thicker than prior art needle cannulas. The thicker sidewall imparts to the needle cannula greater resistance to breakage during the process of injecting animal health products into an animal and greater detectability in a metal detector.
(2) Description of Related Art
Stainless steel alloys are extensively used in manufacturing needle cannulas for hypodermic syringes for injecting animal health products into animals. From time to time, when these needles are used to vaccinate an animal, particularly the large domestic animals used for meat production, a part of the needle cannula breaks off and remains lodged within the flesh of the animal. Because meat containing a broken piece of needle is unfit for human consumption, any meat that contains a broken needle must be separated from the meat that is safe for human consumption.
The meat processing industry uses metal detectors to detect broken needles lodged within the flesh of the animal. However, because the needle cannulas used for veterinary purposes are made from non-magnetic stainless steel alloys, they are difficult to detect with the metal detectors that are used in the meat processing industry. Detection is particularly difficult when the needle's length to diameter ratio is low because at such low ratios the orientation of the needle in the meat affects detectability.
In order to improve detection of these needles, the metal detectors are routinely operated at high sensitivity levels. However, at sensitivity levels the frequency of false positives is increased. Therefore, a greater proportion of meat than is necessary is culled.
Therefore, there is a need for a needle cannula that is more resistant to breakage during the process of injecting animal health products into an animal. There is also a need for a needle cannula that can be readily detected in the metal detectors that are commonly used in the meat processing industry to detect broken needle cannula in the flesh of animals after slaughter.